1. Field of the Invention
The present invention relates to a C-type welding gun provided with an air cylinder, an equalizer disposed over the air cylinder, and a welding transformer disposed over the equalizer.
2. Description of the Prior Art
FIG. 4 shows an arrangement of a prior art C-type welding gun.
The C-type welding gun as illustrated in FIG. 4 comprises an equalizer 21 having a shaft 27 and a rear wall 22 at the rear portion of the shaft 27, an air cylinder 23 having a supporting plate 24 at the rear portion thereof for supporting the equalizer 21 and a front end protruded upward to form a front wall 26 of the equalizer 21, the rear wall 22 of the equalizer 21 being placed on the supporting plate 24 and both the rear wall 22 and the supporting plate 24 being screwed by the bolt 25, 25, a yoke 28 disposed aside the equalizer 21 and the air cylinder 23, the shaft 27 of the equalizer 21 fixed to the front wall 26 of the equalizer 21 and the yoke 28 being retained on the shaft 27 by nuts, 29, 29, and a welding transformer 30 being fixedly mounted on the equalizer 21 by bolts 31, 31.
However, the C-type welding gun having such structure has the following problems.
When the air cylinder 23 is to be replaced with another cylinder in response to the variation of work, firstly the welding transformer 30 is removed from the equalizer 21 by removing the bolts 31, secondly the yoke 28 is removed from the front wall 26 of the equalizer 21 by removing the nuts 29, 29 and at the same time the shaft 27 is removed from the front wall 26, thirdly the rear wall 22 of the equalizer 21 is removed from the supporting plate 24 of the air cylinder 23 by removing the screws 25, 25. Likewise, when the yoke 28 is replaced with another one, the yoke 28 is removed from the shaft 27 by removing the nuts 29, 29. In any event, it is troublesome to replace the air cylinder 23 or the yoke 28.
Inasmuch as the equalizer 21 is disassembled when the air cylinder 23 and the yoke 28 are replaced with other ones, it was hardly possible to assemble the equalizer 21 with high accuracy.